diff options
| -rw-r--r-- | tools/perf/Makefile.perf | 17 | ||||
| -rw-r--r-- | tools/perf/util/Build | 1 | ||||
| -rw-r--r-- | tools/perf/util/bpf_counter.c | 5 | ||||
| -rw-r--r-- | tools/perf/util/bpf_counter_cgroup.c | 307 | ||||
| -rw-r--r-- | tools/perf/util/bpf_skel/bperf_cgroup.bpf.c | 191 | ||||
| -rw-r--r-- | tools/perf/util/cgroup.c | 2 | ||||
| -rw-r--r-- | tools/perf/util/cgroup.h | 1 |
7 files changed, 523 insertions, 1 deletions
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf index c9e0de5b00c1..5ccf6d6adf36 100644 --- a/tools/perf/Makefile.perf +++ b/tools/perf/Makefile.perf @@ -1017,6 +1017,7 @@ SKEL_OUT := $(abspath $(OUTPUT)util/bpf_skel) SKEL_TMP_OUT := $(abspath $(SKEL_OUT)/.tmp) SKELETONS := $(SKEL_OUT)/bpf_prog_profiler.skel.h SKELETONS += $(SKEL_OUT)/bperf_leader.skel.h $(SKEL_OUT)/bperf_follower.skel.h +SKELETONS += $(SKEL_OUT)/bperf_cgroup.skel.h ifdef BUILD_BPF_SKEL BPFTOOL := $(SKEL_TMP_OUT)/bootstrap/bpftool @@ -1030,7 +1031,21 @@ $(BPFTOOL): | $(SKEL_TMP_OUT) CFLAGS= $(MAKE) -C ../bpf/bpftool \ OUTPUT=$(SKEL_TMP_OUT)/ bootstrap -$(SKEL_TMP_OUT)/%.bpf.o: util/bpf_skel/%.bpf.c $(LIBBPF) | $(SKEL_TMP_OUT) +VMLINUX_BTF_PATHS ?= $(if $(O),$(O)/vmlinux) \ + $(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux) \ + ../../vmlinux \ + /sys/kernel/btf/vmlinux \ + /boot/vmlinux-$(shell uname -r) +VMLINUX_BTF ?= $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS)))) + +$(SKEL_OUT)/vmlinux.h: $(VMLINUX_BTF) $(BPFTOOL) +ifeq ($(VMLINUX_H),) + $(QUIET_GEN)$(BPFTOOL) btf dump file $< format c > $@ +else + $(Q)cp "$(VMLINUX_H)" $@ +endif + +$(SKEL_TMP_OUT)/%.bpf.o: util/bpf_skel/%.bpf.c $(LIBBPF) $(SKEL_OUT)/vmlinux.h | $(SKEL_TMP_OUT) $(QUIET_CLANG)$(CLANG) -g -O2 -target bpf -Wall -Werror $(BPF_INCLUDE) \ -c $(filter util/bpf_skel/%.bpf.c,$^) -o $@ && $(LLVM_STRIP) -g $@ diff --git a/tools/perf/util/Build b/tools/perf/util/Build index 1a909b53dc15..2d4fa1304178 100644 --- a/tools/perf/util/Build +++ b/tools/perf/util/Build @@ -141,6 +141,7 @@ perf-y += clockid.o perf-$(CONFIG_LIBBPF) += bpf-loader.o perf-$(CONFIG_LIBBPF) += bpf_map.o perf-$(CONFIG_PERF_BPF_SKEL) += bpf_counter.o +perf-$(CONFIG_PERF_BPF_SKEL) += bpf_counter_cgroup.o perf-$(CONFIG_BPF_PROLOGUE) += bpf-prologue.o perf-$(CONFIG_LIBELF) += symbol-elf.o perf-$(CONFIG_LIBELF) += probe-file.o diff --git a/tools/perf/util/bpf_counter.c b/tools/perf/util/bpf_counter.c index 21c8e71162b1..1d0b9742f727 100644 --- a/tools/perf/util/bpf_counter.c +++ b/tools/perf/util/bpf_counter.c @@ -18,6 +18,7 @@ #include "evsel.h" #include "evlist.h" #include "target.h" +#include "cgroup.h" #include "cpumap.h" #include "thread_map.h" @@ -742,6 +743,8 @@ struct bpf_counter_ops bperf_ops = { .destroy = bperf__destroy, }; +extern struct bpf_counter_ops bperf_cgrp_ops; + static inline bool bpf_counter_skip(struct evsel *evsel) { return list_empty(&evsel->bpf_counter_list) && @@ -759,6 +762,8 @@ int bpf_counter__load(struct evsel *evsel, struct target *target) { if (target->bpf_str) evsel->bpf_counter_ops = &bpf_program_profiler_ops; + else if (cgrp_event_expanded && target->use_bpf) + evsel->bpf_counter_ops = &bperf_cgrp_ops; else if (target->use_bpf || evsel->bpf_counter || evsel__match_bpf_counter_events(evsel->name)) evsel->bpf_counter_ops = &bperf_ops; diff --git a/tools/perf/util/bpf_counter_cgroup.c b/tools/perf/util/bpf_counter_cgroup.c new file mode 100644 index 000000000000..21261f1a0501 --- /dev/null +++ b/tools/perf/util/bpf_counter_cgroup.c @@ -0,0 +1,307 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* Copyright (c) 2021 Facebook */ +/* Copyright (c) 2021 Google */ + +#include <assert.h> +#include <limits.h> +#include <unistd.h> +#include <sys/file.h> +#include <sys/time.h> +#include <sys/resource.h> +#include <linux/err.h> +#include <linux/zalloc.h> +#include <linux/perf_event.h> +#include <api/fs/fs.h> +#include <perf/bpf_perf.h> + +#include "affinity.h" +#include "bpf_counter.h" +#include "cgroup.h" +#include "counts.h" +#include "debug.h" +#include "evsel.h" +#include "evlist.h" +#include "target.h" +#include "cpumap.h" +#include "thread_map.h" + +#include "bpf_skel/bperf_cgroup.skel.h" + +static struct perf_event_attr cgrp_switch_attr = { + .type = PERF_TYPE_SOFTWARE, + .config = PERF_COUNT_SW_CGROUP_SWITCHES, + .size = sizeof(cgrp_switch_attr), + .sample_period = 1, + .disabled = 1, +}; + +static struct evsel *cgrp_switch; +static struct bperf_cgroup_bpf *skel; + +#define FD(evt, cpu) (*(int *)xyarray__entry(evt->core.fd, cpu, 0)) + +static int bperf_load_program(struct evlist *evlist) +{ + struct bpf_link *link; + struct evsel *evsel; + struct cgroup *cgrp, *leader_cgrp; + __u32 i, cpu; + __u32 nr_cpus = evlist->core.all_cpus->nr; + int total_cpus = cpu__max_cpu(); + int map_size, map_fd; + int prog_fd, err; + + skel = bperf_cgroup_bpf__open(); + if (!skel) { + pr_err("Failed to open cgroup skeleton\n"); + return -1; + } + + skel->rodata->num_cpus = total_cpus; + skel->rodata->num_events = evlist->core.nr_entries / nr_cgroups; + + BUG_ON(evlist->core.nr_entries % nr_cgroups != 0); + + /* we need one copy of events per cpu for reading */ + map_size = total_cpus * evlist->core.nr_entries / nr_cgroups; + bpf_map__resize(skel->maps.events, map_size); + bpf_map__resize(skel->maps.cgrp_idx, nr_cgroups); + /* previous result is saved in a per-cpu array */ + map_size = evlist->core.nr_entries / nr_cgroups; + bpf_map__resize(skel->maps.prev_readings, map_size); + /* cgroup result needs all events (per-cpu) */ + map_size = evlist->core.nr_entries; + bpf_map__resize(skel->maps.cgrp_readings, map_size); + + set_max_rlimit(); + + err = bperf_cgroup_bpf__load(skel); + if (err) { + pr_err("Failed to load cgroup skeleton\n"); + goto out; + } + + if (cgroup_is_v2("perf_event") > 0) + skel->bss->use_cgroup_v2 = 1; + + err = -1; + + cgrp_switch = evsel__new(&cgrp_switch_attr); + if (evsel__open_per_cpu(cgrp_switch, evlist->core.all_cpus, -1) < 0) { + pr_err("Failed to open cgroup switches event\n"); + goto out; + } + + for (i = 0; i < nr_cpus; i++) { + link = bpf_program__attach_perf_event(skel->progs.on_cgrp_switch, + FD(cgrp_switch, i)); + if (IS_ERR(link)) { + pr_err("Failed to attach cgroup program\n"); + err = PTR_ERR(link); + goto out; + } + } + + /* + * Update cgrp_idx map from cgroup-id to event index. + */ + cgrp = NULL; + i = 0; + + evlist__for_each_entry(evlist, evsel) { + if (cgrp == NULL || evsel->cgrp == leader_cgrp) { + leader_cgrp = evsel->cgrp; + evsel->cgrp = NULL; + + /* open single copy of the events w/o cgroup */ + err = evsel__open_per_cpu(evsel, evlist->core.all_cpus, -1); + if (err) { + pr_err("Failed to open first cgroup events\n"); + goto out; + } + + map_fd = bpf_map__fd(skel->maps.events); + for (cpu = 0; cpu < nr_cpus; cpu++) { + int fd = FD(evsel, cpu); + __u32 idx = evsel->idx * total_cpus + + evlist->core.all_cpus->map[cpu]; + + err = bpf_map_update_elem(map_fd, &idx, &fd, + BPF_ANY); + if (err < 0) { + pr_err("Failed to update perf_event fd\n"); + goto out; + } + } + + evsel->cgrp = leader_cgrp; + } + evsel->supported = true; + + if (evsel->cgrp == cgrp) + continue; + + cgrp = evsel->cgrp; + + if (read_cgroup_id(cgrp) < 0) { + pr_err("Failed to get cgroup id\n"); + err = -1; + goto out; + } + + map_fd = bpf_map__fd(skel->maps.cgrp_idx); + err = bpf_map_update_elem(map_fd, &cgrp->id, &i, BPF_ANY); + if (err < 0) { + pr_err("Failed to update cgroup index map\n"); + goto out; + } + + i++; + } + + /* + * bperf uses BPF_PROG_TEST_RUN to get accurate reading. Check + * whether the kernel support it + */ + prog_fd = bpf_program__fd(skel->progs.trigger_read); + err = bperf_trigger_reading(prog_fd, 0); + if (err) { + pr_warning("The kernel does not support test_run for raw_tp BPF programs.\n" + "Therefore, --for-each-cgroup might show inaccurate readings\n"); + err = 0; + } + +out: + return err; +} + +static int bperf_cgrp__load(struct evsel *evsel, + struct target *target __maybe_unused) +{ + static bool bperf_loaded = false; + + evsel->bperf_leader_prog_fd = -1; + evsel->bperf_leader_link_fd = -1; + + if (!bperf_loaded && bperf_load_program(evsel->evlist)) + return -1; + + bperf_loaded = true; + /* just to bypass bpf_counter_skip() */ + evsel->follower_skel = (struct bperf_follower_bpf *)skel; + + return 0; +} + +static int bperf_cgrp__install_pe(struct evsel *evsel __maybe_unused, + int cpu __maybe_unused, int fd __maybe_unused) +{ + /* nothing to do */ + return 0; +} + +/* + * trigger the leader prog on each cpu, so the cgrp_reading map could get + * the latest results. + */ +static int bperf_cgrp__sync_counters(struct evlist *evlist) +{ + int i, cpu; + int nr_cpus = evlist->core.all_cpus->nr; + int prog_fd = bpf_program__fd(skel->progs.trigger_read); + + for (i = 0; i < nr_cpus; i++) { + cpu = evlist->core.all_cpus->map[i]; + bperf_trigger_reading(prog_fd, cpu); + } + + return 0; +} + +static int bperf_cgrp__enable(struct evsel *evsel) +{ + if (evsel->idx) + return 0; + + bperf_cgrp__sync_counters(evsel->evlist); + + skel->bss->enabled = 1; + return 0; +} + +static int bperf_cgrp__disable(struct evsel *evsel) +{ + if (evsel->idx) + return 0; + + bperf_cgrp__sync_counters(evsel->evlist); + + skel->bss->enabled = 0; + return 0; +} + +static int bperf_cgrp__read(struct evsel *evsel) +{ + struct evlist *evlist = evsel->evlist; + int i, cpu, nr_cpus = evlist->core.all_cpus->nr; + int total_cpus = cpu__max_cpu(); + struct perf_counts_values *counts; + struct bpf_perf_event_value *values; + int reading_map_fd, err = 0; + __u32 idx; + + if (evsel->idx) + return 0; + + bperf_cgrp__sync_counters(evsel->evlist); + + values = calloc(total_cpus, sizeof(*values)); + if (values == NULL) + return -ENOMEM; + + reading_map_fd = bpf_map__fd(skel->maps.cgrp_readings); + + evlist__for_each_entry(evlist, evsel) { + idx = evsel->idx; + err = bpf_map_lookup_elem(reading_map_fd, &idx, values); + if (err) { + pr_err("bpf map lookup falied: idx=%u, event=%s, cgrp=%s\n", + idx, evsel__name(evsel), evsel->cgrp->name); + goto out; + } + + for (i = 0; i < nr_cpus; i++) { + cpu = evlist->core.all_cpus->map[i]; + + counts = perf_counts(evsel->counts, i, 0); + counts->val = values[cpu].counter; + counts->ena = values[cpu].enabled; + counts->run = values[cpu].running; + } + } + +out: + free(values); + return err; +} + +static int bperf_cgrp__destroy(struct evsel *evsel) +{ + if (evsel->idx) + return 0; + + bperf_cgroup_bpf__destroy(skel); + evsel__delete(cgrp_switch); // it'll destroy on_switch progs too + + return 0; +} + +struct bpf_counter_ops bperf_cgrp_ops = { + .load = bperf_cgrp__load, + .enable = bperf_cgrp__enable, + .disable = bperf_cgrp__disable, + .read = bperf_cgrp__read, + .install_pe = bperf_cgrp__install_pe, + .destroy = bperf_cgrp__destroy, +}; diff --git a/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c b/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c new file mode 100644 index 000000000000..292c430768b5 --- /dev/null +++ b/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c @@ -0,0 +1,191 @@ +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +// Copyright (c) 2021 Facebook +// Copyright (c) 2021 Google +#include "vmlinux.h" +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> +#include <bpf/bpf_core_read.h> + +#define MAX_LEVELS 10 // max cgroup hierarchy level: arbitrary +#define MAX_EVENTS 32 // max events per cgroup: arbitrary + +// NOTE: many of map and global data will be modified before loading +// from the userspace (perf tool) using the skeleton helpers. + +// single set of global perf events to measure +struct { + __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY); + __uint(key_size, sizeof(__u32)); + __uint(value_size, sizeof(int)); + __uint(max_entries, 1); +} events SEC(".maps"); + +// from cgroup id to event index +struct { + __uint(type, BPF_MAP_TYPE_HASH); + __uint(key_size, sizeof(__u64)); + __uint(value_size, sizeof(__u32)); + __uint(max_entries, 1); +} cgrp_idx SEC(".maps"); + +// per-cpu event snapshots to calculate delta +struct { + __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY); + __uint(key_size, sizeof(__u32)); + __uint(value_size, sizeof(struct bpf_perf_event_value)); +} prev_readings SEC(".maps"); + +// aggregated event values for each cgroup (per-cpu) +// will be read from the user-space +struct { + __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY); + __uint(key_size, sizeof(__u32)); + __uint(value_size, sizeof(struct bpf_perf_event_value)); +} cgrp_readings SEC(".maps"); + +const volatile __u32 num_events = 1; +const volatile __u32 num_cpus = 1; + +int enabled = 0; +int use_cgroup_v2 = 0; + +static inline int get_cgroup_v1_idx(__u32 *cgrps, int size) +{ + struct task_struct *p = (void *)bpf_get_current_task(); + struct cgroup *cgrp; + register int i = 0; + __u32 *elem; + int level; + int cnt; + + cgrp = BPF_CORE_READ(p, cgroups, subsys[perf_event_cgrp_id], cgroup); + level = BPF_CORE_READ(cgrp, level); + + for (cnt = 0; i < MAX_LEVELS; i++) { + __u64 cgrp_id; + + if (i > level) + break; + + // convert cgroup-id to a map index + cgrp_id = BPF_CORE_READ(cgrp, ancestor_ids[i]); + elem = bpf_map_lookup_elem(&cgrp_idx, &cgrp_id); + if (!elem) + continue; + + cgrps[cnt++] = *elem; + if (cnt == size) + break; + } + + return cnt; +} + +static inline int get_cgroup_v2_idx(__u32 *cgrps, int size) +{ + register int i = 0; + __u32 *elem; + int cnt; + + for (cnt = 0; i < MAX_LEVELS; i++) { + __u64 cgrp_id = bpf_get_current_ancestor_cgroup_id(i); + + if (cgrp_id == 0) + break; + + // convert cgroup-id to a map index + elem = bpf_map_lookup_elem(&cgrp_idx, &cgrp_id); + if (!elem) + continue; + + cgrps[cnt++] = *elem; + if (cnt == size) + break; + } + + return cnt; +} + +static int bperf_cgroup_count(void) +{ + register __u32 idx = 0; // to have it in a register to pass BPF verifier + register int c = 0; + struct bpf_perf_event_value val, delta, *prev_val, *cgrp_val; + __u32 cpu = bpf_get_smp_processor_id(); + __u32 cgrp_idx[MAX_LEVELS]; + int cgrp_cnt; + __u32 key, cgrp; + long err; + + if (use_cgroup_v2) + cgrp_cnt = get_cgroup_v2_idx(cgrp_idx, MAX_LEVELS); + else + cgrp_cnt = get_cgroup_v1_idx(cgrp_idx, MAX_LEVELS); + + for ( ; idx < MAX_EVENTS; idx++) { + if (idx == num_events) + break; + + // XXX: do not pass idx directly (for verifier) + key = idx; + // this is per-cpu array for diff + prev_val = bpf_map_lookup_elem(&prev_readings, &key); + if (!prev_val) { + val.counter = val.enabled = val.running = 0; + bpf_map_update_elem(&prev_readings, &key, &val, BPF_ANY); + + prev_val = bpf_map_lookup_elem(&prev_readings, &key); + if (!prev_val) + continue; + } + + // read from global perf_event array + key = idx * num_cpus + cpu; + err = bpf_perf_event_read_value(&events, key, &val, sizeof(val)); + if (err) + continue; + + if (enabled) { + delta.counter = val.counter - prev_val->counter; + delta.enabled = val.enabled - prev_val->enabled; + delta.running = val.running - prev_val->running; + + for (c = 0; c < MAX_LEVELS; c++) { + if (c == cgrp_cnt) + break; + + cgrp = cgrp_idx[c]; + + // aggregate the result by cgroup + key = cgrp * num_events + idx; + cgrp_val = bpf_map_lookup_elem(&cgrp_readings, &key); + if (cgrp_val) { + cgrp_val->counter += delta.counter; + cgrp_val->enabled += delta.enabled; + cgrp_val->running += delta.running; + } else { + bpf_map_update_elem(&cgrp_readings, &key, + &delta, BPF_ANY); + } + } + } + + *prev_val = val; + } + return 0; +} + +// This will be attached to cgroup-switches event for each cpu +SEC("perf_events") +int BPF_PROG(on_cgrp_switch) +{ + return bperf_cgroup_count(); +} + +SEC("raw_tp/sched_switch") +int BPF_PROG(trigger_read) +{ + return bperf_cgroup_count(); +} + +char LICENSE[] SEC("license") = "Dual BSD/GPL"; diff --git a/tools/perf/util/cgroup.c b/tools/perf/util/cgroup.c index e819a4f30fc2..851531102fd6 100644 --- a/tools/perf/util/cgroup.c +++ b/tools/perf/util/cgroup.c @@ -18,6 +18,7 @@ #include <regex.h> int nr_cgroups; +bool cgrp_event_expanded; /* used to match cgroup name with patterns */ struct cgroup_name { @@ -484,6 +485,7 @@ int evlist__expand_cgroup(struct evlist *evlist, const char *str, } ret = 0; + cgrp_event_expanded = true; out_err: evlist__delete(orig_list); diff --git a/tools/perf/util/cgroup.h b/tools/perf/util/cgroup.h index de5b272560ab..12256b78608c 100644 --- a/tools/perf/util/cgroup.h +++ b/tools/perf/util/cgroup.h @@ -18,6 +18,7 @@ struct cgroup { }; extern int nr_cgroups; /* number of explicit cgroups defined */ +extern bool cgrp_event_expanded; struct cgroup *cgroup__get(struct cgroup *cgroup); void cgroup__put(struct cgroup *cgroup); |